Mid-exhaust steam-engine.



H. LENTZ.

MID EXHAUST STEAM'ENGINE. APPLICATIVON Him SEPT-23. I914.

20, 1917. 3 SHEETS-SHEET I.

Patented Nov.

IN VE N TOR WITNESSES.

" 'ATTOfM/Y H. LENTZ.

MID EXHAUST STEAM ENGINE. APPLICATION FILED SEPT- 23'. 1914.

Patented Nov. 20, 1917.

3 SHEETS-SHEET 2- WITNESSES IIVI/ENTOR'.

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Patented Nov. 20, 1917..

3 SHEETS-SHEET 3.

' ton and a valve in series HUGO LENTZ, OF HALENSEE, NEAR BERLIN, GERMANY.

mm-nxnnos'r smart-ENG NE.

, Specification of Letters Patent.

Patented Nov. 20, 1917.

Application filed September 23, 1914. Serial No. 868,061.

To all whom it may concern:

Be it known that I, Hoco LnN'rz, a cit1zen of the German Empire, and residing at Halensee, near Berlin, Germany, have mvented certain new and useful Improvements in Mid-Exhaust Steam-Engines, of which the following is a specification.

This invention relates to midsexhaust steam engines of the type comprising exhaust ports controlled by the working pistherewith.

A primary object is to provide an improved exhaust valve such that this controls not only the inlet valves of the cylinder but at the same time an auxiliary exhaust which automatically operates when the compression in the cylinder has attained an inadmissible amount or when a change is made from working with condensation to noncondensation. 1

Another object of the invention is to arrange the distributing edges of the valve relatively to the edges of the cams provided thereon for the inlet valves in, such manner that it is possible to machine the valve in a simple manner and in such a manner that the constrictions in the exhaust port are done away with.

seen from below;

'part of Fig. 1;

To these ends my invention consists in the construction, arrangement and combination of parts described hereinafter and pointed out in the claims. I

One illustrative embodiment of the invention as applied to a compound steam en- 'ne which compr '1ses a low-pressure midexhaust cyllnder is represented by way of example in the j accompanying drawings,

wherein:

Figure 1 is a cross-section taken on the line 1-1 in Fig. 4,

Fig. 2 shows two vertical sections taken through the engine shown in'Fig. 1, the lefthand side .being taken on the line 2-2 and on the right-hand on the bent line 2-2' in Fig. 1, 4 v

Fig. 3 is a cross-section taken on the bent line 33 in Fig. 4, and

Fig. 4 is a horizontal section taken on the line 4-4 in Fig. 3, the upperpart being as seen from above and the lower part as Fig- 5 is an enlarged .view (if the-lower Figs. 6,7 and 8 are detail sectional views through-the-distributing valve taken on the lines 6-.6, 7-7 and 88, respectively, in Fig. 5, and 1 Fig. 9 is a cross-sectional view taken on line 99 of Fig. 5, looking in the direction of the arrow. Referring to the drawings, the illustrated compound steamengine of the Woolf type comprlses a high-pressure cylinder 0 and a low-pressure cylinder a respectively containing the working pistons a and b (Fig. 4). The two cylinders are connected to-' gether at their ends by passage ways a and 0'. Live steam enters at (1, passes throughthe inlet valves 19 and the passage ways into the high-pressure cylinder 0, flows hence after partially 'expandingthrough the passage ways a and the intermediate valves cams 71 arranged in'known manner immediately at the exhaust valve f. These cams i coact with the ends of the valve rods Z.

The escape of the steam from the lowpressure cylinder a through. the exhaust ports e is regulated by the and the rotary valve 7. rotary valve which covers the exhaust ports e has the'section f shown in Fig. 8 and according to its position for the time 'bein closes or opens these ports e. The valve is controlled by an eccentric, not shown,

7 whose rod is attached to the rocking lever]; n

Besides the distributing ports descri above additional auxiliary exhaust ports is working piston 12 The part of this (Fig. 4) are arranged along the low-pres:

sure cylinder n which open at one end by way of vertical holes k into the cylinder ends and at the other end into a hole s'- in the middle support 8 containing the rotary valve f, and thus establish a connection between the' cylinder ends and the." exhaust lished.v

auxiliary valve the ports chamber. In the position of the rotary valve 7 shoWn in Fig. 5,-however, these ports 11 are constantly closed by the full section if of the valveeven When the valve 7 is rotated. With the-partsin their posltions shown in Figs. 1 and 5 the condenser .is in operation and the low-pressure cylinder works on the pure direct-current or midexhaust-principle.

The smaller section u is formed beside the full section a by means of a recess, and the dsstributing edges 3 of this section u have the position represented in ig. 7 relatively to the ports It; This auxillary valve u is intended to act only when, owing to the condensing plant breaking down or to any other reason, the pressure in the low-pressure cylinder exceeds the admissible amount, because then owing to the insertion of this h are alternately opened and closed'and a connection of the cylinder ends with the exhaust is estab- The engine thenworks in part 'on the counter-current principle.

In order that the valve u may operate automatically when the condensing plant breaks down, the entire exhaust valve f is mounted displaceably'in a casing g, and the one end like a piston closes'a space or chamber g in the casing 9, this space or chamber being connected by a tube a with the condenser, so that the pressure of the condenser at any time exists in this space. A spring w in this chamber 9 serves for shifting to the right the distributing valve f when the condenser is not operating. When the condensing plant is working the'full pressure below atmospheric exists in thechamber 9, so thatthe entire valve f is then shifted to the left and the solid part of the valve constantly closes the auxiliary. exhaust ports is. If the condensing pressure in the "0 amber g consequently rises the spring w operates, shifts the valve to the right and renders the part u of the valve operative.

In order that the rotary valve 7 may continue to be driven during-this displacement its other end has a rectangular projection f that is clasped as by a claw by the forked end 9' of the driving lever 9. By this means the valve member. f may be moved to the position shown in Figs. 1 and 5 while continuing to be operated by the lever 'g. The movement of the valve member to the left (Fig. 5) is limited by the stop 10, while its movement to the right is limited by the inner end 9" of-the bearing memberfor the claw g. The inner end 9 of this member is arranged slightly eccentric wi'th respect to the adjacent bore for the valve member and the end 9" engages the adjacent portion of the A valve member f to limit its movements to the right.

Referring to Figs. 6 and 8, it will be ob dicated in Fig. 8

- is uniform throughout its lant breaks down and the served that the cam 11 for controlling the valve spindles Z, Z also controls the portion of the long narrow exhaust port at that location, and if in designing this cam a due regard were not given to the width of the exhaust ort along the remaining portion of itslengt ,and to the width or angular embrace of the port-closing portion of the valve member 7', the extremities of which are inby the numerals 4:, 4, some special shape would have to be given to the portion of the exhaust port controlled by said cam, in order that no steam would flow out at this point before it would along the rest of the exhaust port. In order to obviate this, I so design the cam i that the width or angular embrace of its 2+2, as shown in Fig. 6, is equal to the width or angular embrace of the upper portion of the cam member f which controls the remaining length of the exhaust port, so that the width of the top or exhaust portcontrolling portion of the valve member f length except at the central portion ut controlling the auxiliary exhaust port 70. By this arrangement the said exhaust port e can be made uniform throughout and the entire valve member f may be more readily made because it can be simply milled; shallow recesses being necessary only where the cams are located.

I claim I 1. In a steam engine, a cylinder having a main exhaust; port and an auxiliary exhaust port intermediate said ment and for opening and closing one of said ports and keeping the other closed under another adjustment.

2. In a steam engine, the combination of a cylinder having a main exhaust port and an auxiliary exhaust port intermediate said main exhaust port and one'end of the cylinder, adjustable means for ing both of said ports under one adjustment and for opening and closing one of said ports and keeping the other closed under another adjustment,and means responsive to thepressure in the exhaust passage of the engine for setting said last named means at its adjusted positions.

3. Ina steam engine, thecombination of a .cylinder having a mid-exhaust ort and other. exhaust ports, one interme iate the mid-exhaust port and each end of inder, and valve mechanism for controlling said exhaust ports, said mechanism having means for controlling the mid-exhaust port independently of the other exhaust ports.

In a steam engine, the combination of a cylinder having a mid-exhaust port and the cylinders, and a rocking valve member for the combination of opening and closthe cylcontrolling said exhaust ports, said'member having means for opening and closing. the

6. In a steam engine, the combination of a cylinder having .a mid-exhaust port and auxiliary exhaust ports, one intermediate the mid-exhaust port and each end of the opening cylinder, a rock shaft having provision for opening and closing the mid-exhaust port and for maintaining the auxiliary exhaust ports closed during normal operation of the engine, and means for shifting said shaft to a position wherein it also opens and closes the auxiliary exhaust ports.

7 In a steam engine, the combination of a cylinder having a mid-exhaust port and auxiliary exhaust ports, one intermediate the mid-exhaust ort and each end of the cylinder, a roc -shaft having provision for and closing the mid-exhaust port and for maintaining the auxiliary exhaust ports closed during normal operation of the engine, said shaft and dependent upon the pressure in the exhaust passage of the engine'for shifting the shaft uponpredetermined increases of said pressure to a position wherein it also opens and closes the auxiliary ports.

8. In a steamengine, the combination of cylinder having a mid-exhaust port and auxiliary exhaust ports, one intermediate the mid-exhaust port and each end of the cylinder, a valve member, means for rocking the same to control the ports, means responsive to pressure in the exhaust passage of the engine for shifting the valve member in the direction of itslen'gth, a valve surface for controlling the opening and closing of said mid-exhaust port, and

having a valve surface for closing the auxiliary ports through the rocking arc ofthe member, and also having a surface for opening and closing said auxiliary ports whenthe member is shlfted responsive to change in said pressure. 4

9. In a steam engine, the combination of a cylinder having a mid-exhaust port and a main exhaust passage leading therefrom,

. auxiliary exhaust ports one mtermediate cylinder,

and each end of the and passages leading from said last named ports to said main exhaust pasthe mid-exhaust port and closing... the mid? 1 and means operatively related to said member having sage, *exhaust passage independently of said auxiliary exhaust passages.

10. In a steam engine, a cylinder having a mid-exhaust port and a main exhaust passage leading therefrom,

auxiliary exhaust portsone intermediate the and means for controlling said main the combination of 'sai-d rnain passage and keeping closed said auxiliary passages under another adjustment.

'11. ,In a steam engine, the combination of. .a cylinder having mid-exhaust ports and auxiliary exhaust ports, shaft mounted for rocking movement and longitudinal shifting, means for rocking said shaft, said means being connected thereto to permit relative closing the mid-exhaust port and for maintaining the auxiliary ports closed, and means for shifting the shaft to a position wherein it also opens and closes the. auxiliary exhaust ports.

12. In a steam engine, auxiliary exhaust ports, a valve-control shaft mounted for rocking movement and longitudinal shifting, said. shaft having a longitudinally extending arcuate face for controlling the opening and closing of said mid-1 exhaust port, said face having a width equal to or greater than the width of said midexhaust port, said face having arcuate extensions for closing said auxiliary exhaust passages at all times during the rocking movement of said shaft, said face having additionalextensions of lesser extent than said last named extensions and adapted to open and close said auxiliary exhaust ports shift said shaft.

longitudinal movement, said shaft having provision for opening and the combination ofl a cylinder having a mid-exhaustport and a valve-control 13. In a steam engme, the combination of a cylinder having a mid-exhaust port and auxiliary exhaust ports, a valve-control shaft having circular journal portions, and means for opening and closing said ports when in one position and for opening an closing certain of saidports and keeping closed certain of said ports when in another position, said cylinder'having bear ings to accommodate said'journal portions, a chamberformed around the end of one of said bearings, said chamber communicatin with the exhaust passage of the engine, a g means to rock said shaft. 14. In a steam engine, the combination of a ,cylinder having a mid-exhaust port and auxiliary exhaust ports, a valve-control shaft having circular journal portions. and means ber formed around the end of one of said bearings, a spring in said chamber and pressing against said shaft, an oscillating member, and means coupling said member and shaft to transmit rotary movement and permit relative longitudinal movement.

15. In a steam engine, the combination of i a cylinder having a mid-exhaust port and other exhaust ports, and a single adjustable valve member for opening and closing all of said ports under one adjustment, and forv opening and closing certain ofsaid ports and keeping closed certain of said ports under another adjustment.

In testimony whereof, I aflix my signature in the presence of two witnesses.

HUGO LENTZ; Witnesses: c

HENRY HASPER, WOLDEMAR HAUPT. 

